His first assignment: Identify the vowel pattern in “Maine.” Using a computer touch screen, he dragged the word under a column labeled “ai.”

Thankfully for the visitor – former President George W. Bush – he got it right.

The one-time Texas governor made a rare public appearance, touring the KIPP campus and meeting with Houston education leaders to discuss the importance of recruiting and training top-notch principals.

Bush steered clear of the controversy around his signature education law, No Child Left Behind, and Texas’ recent announcement that it would seek an exemption from its requirements.

But the 66-year-old, looking tan and trim, doled out advice to students – study hard, exercise, vote – and touted principals as key to improving learning.

At a roundtable discussion that included his former education secretary, Rod Paige, Bush recalled meeting a school leader and questioning his credentials.

George W. Bush interacts with second graders. (Karen Warren/Houston Chronicle)

“How’d you get to be the principal?” Bush asked. The reply: “I was the coach.”

Through his Dallas-based nonprofit, the George W. Bush Institute, the former president has helped bring together leaders of principal-preparation programs to share ideas with schools across the country. The network, called the Alliance to Reform Education Leadership, includes training programs run by KIPP and Rice University.

Improving the quality of teachers has been a hot-button issue nationwide, but policymakers have focused less on principals.

“You can’t have a good school until you have an innovative, well trained principal,” Bush said.

Principals from HISD, KIPP and the YES Prep charter school in the North Forest district agreed during the talk that keys to their success were having mentors to call and, in some cases, a year to shadow a seasoned leader.

Terry Grier, the superintendent of the Houston Independent School District, noted that Texas law gives charter schools more freedom in hiring principals.

Bush, sitting across the table from Grier, leaned forward and posed a challenge. Bush said that as governor he supported a 1995 law that allowed traditional school systems to break free from some state mandates by seeking voter approval to become a “home-rule” charter district.

“If you truly want to be apart from the state,” Bush said, “get your school board to hold an election and say, ‘We secede.'”

Grier said in an interview later that he was unaware of the law.

Proud students with their VIP visitor. (Karen Warren/Houston Chronicle)

“Let’s just say, it piqued enough interest for me to find out about it. It would be pretty wild,” he said. “Hopefully this legislative session, we can convince some folks to give us some of the flexibility that charters enjoy and make good use of.”

David Thompson, a school attorney and former general counsel of the Texas Education Agency, said he doesn’t think any districts have sought home-rule, mostly because the law doesn’t grant them as much freedom as regular charter schools. Those charters don’t have to abide by class size caps, for example, and have an easier time ousting poor-performing teachers.

The conversations were lighter in the classrooms.

Bush told a group of sixth-graders that he’s been taking oil painting lessons and is working on a portrait of his Scottish Terrier, Barney.

“You can keep learning. That’s my point,” Bush told the students.

Later came a hardball question from a boy in the back of the room: “Are you a bodybuilder?”

“No,” Bush said with a smile. “Can’t you tell? I ride mountain bikes.”